The invention relates to containers constructed to meet specific requirements regarding size, strength, mechanical construction, and the like. Especially containers used for the air transport of goods must meet stringent requirements. Such air cargo containers must be capable of sustaining acceleration forces up to twelve times the force of gravity without being damaged. These transport containers may be used, for example, to carry food for aircraft passengers. The contents of the containers should preferably be accessible from the front and back for the efficient removal of the content simultaneously from both ends.
A sandwich type construction of aluminum hard-foam aluminum is used for the doors and side walls of transport containers according to the prior art. A supporting framework provides the required strength and stability for containers with such sandwich type wall and door constructions. The same requirements apply to containers having doors on their sides, containers which are loaded from the top, so called open top containers, and containers substantially without side panels, so called "flats".
The corner and edge connections of the frame of the containers must be able to withstand the expected stresses, such as those resulting form the above mentioned acceleration forces. The structural features determine the economy of such transport containers. Welding has been used in the construction of some containers. Other container constructions employ corner or edge elements having a number of extensions, such as pins, or tenons fitting into connecting tubes, or rails, and connected by securing elements. Such structures are known from the metal aircraft manufacture. The tensile and compressive forces which act on the corners are taken up by the securing elements themselves, for example, by cotter pins, rivets, screws, or the like. Thus, friction between the parts to be interlocked to form the containers is not utilized in the prior art.
Metal adhesives are also used in container constructions of the prior art. These metal adhesives have the disadvantage that connections are difficult to loosen when a part must be exchanged, or repaired. The aging of the metal adhesives is another prior art disadvantage also limiting the use of adhesives in the construction of containers.
As explained above, a transport container of this type often has two doors located on opposite sides of the container for simultaneous opening and maximum accessability. Thus, the frame of the remaining four container walls must be stable even when the doors are opened at the same time. Both the hinges and the striking sides of the doors are subject to substantial stresses since these connections between the frame and the doors proper are subject to all the effective forces including the loads of the container content, which definitely must not be spilled.
Prior art constructions of the hinges require high installation expenditures, especially due to the piano type of hinges used heretofore. Another disadvantage of previously known hinges is that a damaged door required time-consuming repairs and cleaning was difficult due to the delicate structure of the hinge elements.
The inaccurate final opening angle of previously known hinges often results in damaged doors and walls calling for frequent repairs.